We are investigating development and plasticity of the rat's visual system. Work involves lesions made early in development and transplantation of tissues from one animal to another. From this we hope to gain information as to factors regulating growth and formation of specific neural connections in the developing mammalian brain. BIBLIOGRAPHIC REFERENCES: Wise, R.P. and R.D. Lund 1976. The retina and central projects of heterochromic rats. Exp. Neurol., 51: 68-77. Mustari, M.J. and R.D. Lund 1976. An aberrant crossed visual corticotectal pathway in albino rats. Brain Res., 112:37-44.